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TRANSCRIPT
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BGP PART 1
Well-known Mandatory Must be supported and propagated
Attribute Types
Well-known Discretionary Must be supported; propagation optional
Optional Transitive Marked as partial if unsupported by neighbor
Optional Nontransitive Deleted if unsupported by neighbor
Type
About BGP
eBGP AD
iBGP AD
Path Vector
20
200
Standard
Protocols
Transport
Authentication
RFC 4271
IP
TCP/179
MD5
AttributesName
Aggregator OTID and AS of router which performedsummarization
Type Description
List of autonomous systems which theadvertisement has traversed
AS Path WM
Atomic Aggregate WDIncludes ASes which have been droppeddue to route aggregation
Originating clusterONCluster ID
Route tagOTCommunity
Metric for internal neighbors to reachexternal destinations (default 100)
Local Preference WD
Multiple ExitDiscriminator (MED)
ONMetric for external neighbors to reachthe local AS (default 0)
External peer in neighboring ASWMNext Hop
Origin type (IGP, EGP, or unknown)WMOrigin
Identifies a route reflectorONOriginator ID
Weight OCisco proprietary, not communicated topeers (default 0)
Path Selection
Attribute
Weight Administrative preference
Description
1
Preference
Highest
Local PreferenceCommunicated between peerswithin an AS
2 Highest
Self-originated Prefer paths originated locally3 True
AS Path Minimize AS hops4 Shortest
OriginPrefer IGP-learned routes overEGP, and EGP over unknown
5 IGP
MED Used externally to enter an AS6 Lowest
External Prefer eBGP routes over iBGP7 eBGP
IGP Cost Consider IGP metric8 Lowest
eBGP Peering Favor more stable routes9 Oldest
Router ID Tie breaker10 Lowest
Influencing Path Selection
Weight neighbor 172.16.0.1 weight 200
MED default-metric 400
Local Preference bgp default local-preference 100
Route Map neighbor 172.16.0.1 route-map Fo
Terminology
Autonomous System (AS)A logical domain under the control of a
single entity
External BGP (eBGP)BGP adjacencies which span autonomo
system boundaries
Internal BGP (iBGP)BGP adjacencies formed within a singleautonomous system
Synchronization RequirementA route must be known by an IGP befo
it may be advertised to BGP peers
Packet Types
Open Update
Keepalive Notification
Neighbor States
Idle Neighbor is not responding
Connect TCP session established
Open Sent Open message sent
Open Confirm Response receive
Established Adjacency establishe
Troubleshooting
show ip bgp [summary]
show ip bgp neighbors
show ip route [bgp]
clear ip bgp * [soft]
debug ip bgp []
Active Attempting to connect
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BGP PART 2Configuration Example
interface Serial1/0description Backbone to Bip address 172.16.0.1 255.255.255.252!interface Serial1/1description Backbone to Cip address 172.16.0.5 255.255.255.252
!interface FastEthernet2/0description LANip address 192.168.1.1 255.255.255.0!router bgp 65100no synchronizationnetwork 172.16.0.0 mask 255.255.255.252network 172.16.0.4 mask 255.255.255.252network 192.168.1.0neighbor South peer-groupneighbor South remote-as 65200neighbor 172.16.0.2 peer-group Southneighbor 172.16.0.6 peer-group South
no auto-summary
10.0.0.0/30
172.16.0.0/30172.16.0.4/30
AS 65100
AS 65200
F0/0 F0/0
A
B C
OSPF
F2/0 F2/0
S1/0S1/0
S1/0 S1/1
F2/0
interface FastEthernet0/0description Backbone to Bip address 10.0.0.2 255.255.255.252!interface Serial1/0description Backbone to Aip address 172.16.0.6 255.255.255.252!interface FastEthernet2/0description LANip address 192.168.3.1 255.255.255.0!
router ospf 100network 10.0.0.2 0.0.0.0 area 0network 192.168.3.1 0.0.0.0 area 2!router bgp 65200no synchronizationredistribute ospf 100 route-map LAN_Subnetsneighbor 10.0.0.1 remote-as 65200neighbor 172.16.0.5 remote-as 65100no auto-summary!access-list 10 permit 192.168.0.0 0.0.255.255!route-map LAN_Subnets permit 10
match ip address 10set metric 100
interface FastEthernet0/0description Backbone to Cip address 10.0.0.1 255.255.255.252!interface Serial1/0description Backbone to Aip address 172.16.0.2 255.255.255.252!interface FastEthernet2/0description LANip address 192.168.2.1 255.255.255.0!
router ospf 100network 10.0.0.1 0.0.0.0 area 0network 192.168.2.1 0.0.0.0 area 1!router bgp 65200no synchronizationredistribute ospf 100 route-map LAN_Subnetsneighbor 10.0.0.2 remote-as 65200neighbor 172.16.0.1 remote-as 65100no auto-summary!access-list 10 permit 192.168.0.0 0.0.255.255!route-map LAN_Subnets permit 10
match ip address 10set metric 100
Router A Routing Table Router B Routing Table
172.16.0.0/30 is subnetted, 2 subnetsC 172.16.0.4 is directly connected, S1/1C 172.16.0.0 is directly connected, S1/0C 192.168.1.0/24 is directly connected, F2/0B 192.168.2.0/24 [20/100] via 172.16.0.2B 192.168.3.0/24 [20/100] via 172.16.0.2
172.16.0.0/30 is subnetted, 2 subnetsB 172.16.0.4 [20/0] via 172.16.0.1C 172.16.0.0 is directly connected, S1/0
10.0.0.0/30 is subnetted, 1 subnetsC 10.0.0.0 is directly connected, F0/0B 192.168.1.0/24 [20/0] via 172.16.0.1C 192.168.2.0/24 is directly connected, F2/0O IA 192.168.3.0/24 [110/2] via 10.0.0.2, F0/0
Route
RouteRouter B
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CISCO IOS VERSIONSIOS Nomenclature Release Lifecycle
EOS NoticeNotification of upcoming EOS
First Customer Shipment (FCS)The release is made available to Cisco customers on CCO
IOS Version Verification
show version
dir :
verify :
End of Sale (EOS)The release is no longer orderable or included inmanufactured shipments
End of Engineering (EOE)The last day for software fixes; only TAC assistance is offefrom this point
End of Life (EOL)The last day for TAC support; release becomes obsolete;upgrade is only option for continued support
EOS Notice
EOS
EOE
EOL
IOS Package Trees
Advanced IP Services
Advanced Enterprise Services
Enterprise Services
Advanced
SecuritySP Services
Enterprise
Base
IP Voice
IP Base
Advanced Enterprise Services
Advanced IP Services Enterprise Services
IP Base
IP Services
IOS Filename
c3725-entbase-mz.124-6.T.bi
Hardware
Feature Set
Memory LocationCompression Format
Maintenance Release
Individual Release
T Designator
Deployment Classifications
3.2.1Major Release
Minor Release
Maintenance Release
IOS XR
12.2(25)SEB4Release
Individual Release
Numbered Version
S Train
12.4(9)T1Maintenance Release
Individual Release
New Feature Identifier
Numbered Version
T Train
12.4(7a)Maintenance Release
Individual Release
Numbered Version
Mainline
General Deployment (GD)A major release considered qualified for deployment oncritical devices
Early Deployment (ED)Offers new feature, platform, or interface support
Deferred (DF)Known defective images; should not be installed
Limited Deployment (LD)A major release prior to reaching its GD milestone
0 12 24 36 48 60 72 84
Months
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CISCO IOS VERSIONSIOS Nomenclature Release Lifecycle
EOS NoticeNotification of upcoming EOS
First Customer Shipment (FCS)The release is made available to Cisco customers on CCO
IOS Version Verification
show version
dir :
verify :
End of Sale (EOS)The release is no longer orderable or included inmanufactured shipments
End of Engineering (EOE)The last day for software fixes; only TAC assistance is offefrom this point
End of Life (EOL)The last day for TAC support; release becomes obsolete;upgrade is only option for continued support
EOS Notice
EOS
EOE
EOL
IOS Package Trees
Advanced IP Services
Advanced Enterprise Services
Enterprise Services
Advanced
SecuritySP Services
Enterprise
Base
IP Voice
IP Base
Advanced Enterprise Services
Advanced IP Services Enterprise Services
IP Base
IP Services
IOS Filename
c3725-entbase-mz.124-6.T.bi
Hardware
Feature Set
Memory LocationCompression Format
Maintenance Release
Individual Release
T Designator
Deployment Classifications
3.2.1Major Release
Minor Release
Maintenance Release
IOS XR
12.2(25)SEB4Release
Individual Release
Numbered Version
S Train
12.4(9)T1Maintenance Release
Individual Release
New Feature Identifier
Numbered Version
T Train
12.4(7a)Maintenance Release
Individual Release
Numbered Version
Mainline
General Deployment (GD)A major release considered qualified for deployment oncritical devices
Early Deployment (ED)Offers new feature, platform, or interface support
Deferred (DF)Known defective images; should not be installed
Limited Deployment (LD)A major release prior to reaching its GD milestone
0 12 24 36 48 60 72 84
Months
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EIGRPProtocol Header
Type
Attributes
Algorithm
Internal AD
External AD
Distance Vector
DUAL
90
170
Summary AD
Standard
Protocols
Transport
5
Cisco proprietary
IP, IPX, Appletalk
IP/88
Version Opcode Checksum
8 16 24 32
Flags
Sequence Number
Acknowledgment Number
Autonomous System Number
Type Length
Value
Authentication
Multicast IP
Hello Timers
Hold Timers
MD5
224.0.0.10
5/60
15/180
Metric Formula
256 * (K1 * bw + + K3 * delay) *K2 * bw
256 - load
K5
rel + K4
bw = 107/ minimum path bandwidth in kbps delay = interface delay in secs / 10
EIGRP Configuration
! Enable EIGRProuter eigrp
! Add networks to advertisenetwork
! Configure K values to manipulate metric formulametric weights 0
! Disable automatic route summarizationno auto-summary
! Designate passive interfacespassive-interface ( | default)
! Enable stub routingeigrp stub [receive-only | connected | static | summary]
! Statically identify neighoring routersneighbor
Protocol Configuration
! Set maximum bandwidth EIGRP can consumeip bandwidth-percent eigrp
! Configure manual summarization of outbound routesip summary-address eigrp []
! Enable MD5 authenticationip authentication mode eigrp md5ip authentication key-chain eigrp
! Configure hello and hold timersip hello-interval eigrp ip hold-time eigrp
! Disable split horizon for EIGRPno ip split-horizon eigrp
Interface Configuration
K Defaults Packet Types
K1 1
K2 0
K3 1
K4 0
K5 0
1 Update
3 Query
4 Reply
5 Hello
8 Acknowledge
Terminology
Feasible DistanceThe distance advertised by a neighbor plus the cos
to get to that neighbor
Reported DistanceThe metric for a route advertised by a neighbor
Stuck In Active (SIA)The condition when a route becomes unreachableand not all queries for it are answered; adjacencie
with unresponsive neighbors are reset
Passive InterfaceAn interface which does not participate in EIGRP bwhose network is advertised
Stub RouterA router which advertises only a subset of routes,and is omitted from the route query process
Troubleshooting
show ip eigrp interfaces
show ip eigrp neighbors
show ip eigrp topology
show ip eigrp traffic
clear ip eigrp neighbors
debug ip eigrp [packet | neighbors]
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FIRST HOP REDUNDANCYProtocols
HSRP Configuration
interface FastEthernet0/0ip address 10.0.1.2 255.255.255.0standby version {1 | 2}standby 1 ip 10.0.1.1standby 1 timers standby 1 priority standby 1 preemptstandby 1 authentication md5 key-string standby 1 track standby 1 track decrement
Troubleshooting
show standby [brief]
show glbp [brief]
Virtual Router Redundancy Protocol (VRRP)An open-standard alternative to Cisco's HSRP,
providing the same functionality
Hot Standby Router Protocol (HSRP)Provides default gateway redundancy using one activeand one standby router; standardized but licensed byCisco Systems
Gateway Load Balancing Protocol (GLBP)Supports arbitrary load balancing in addition toredundancy across gateways; Cisco proprietary
Attributes
HSRP
NoLoad Balancing
RFC 2281Standard
Transport
IPv6 Support
Default Hello
Default Priority
Multicast Group
UDP/1985
Yes
3 sec
100
224.0.0.2
VRRP
No
RFC 3768
IP/112
No
1 sec
100
224.0.0.18
GLBP
Yes
Cisco
UDP/322
Yes
3 sec
100
224.0.0.1
HSRP VRRP GLBP
Standby Active Listen
100 200 100
Backup Master
100 200 100
Backup
VRRP Configuration
interface FastEthernet0/0ip address 10.0.1.2 255.255.255.0vrrp 1 ip 10.0.1.1vrrp 1 timers {advertise | learn}vrrp 1 priority vrrp 1 preemptvrrp 1 authentication md5 key-string vrrp 1 track decrement
GLBP Configuration
interface FastEthernet0/0ip address 10.0.1.2 255.255.255.0glbp 1 ip 10.0.1.1glbp 1 timers glbp 1 timers redirect glbp 1 priority glbp 1 preemptglbp 1 forwarder preemptglbp 1 authentication md5 key-string glbp 1 load-balancing glbp 1 weighting lower upper glbp 1 weighting track decrement
Speak Gateway election in progress
HSRP/GLBP Interface States
Active Active router/VG
Standby Backup router/VG
Listen Not the active router/VG
Master Acting as the virtual router
VRRP Interface States
Backup All non-master routers
GLBP Roles
Active Virtual Gateway (AVG)Answers for the virtual router and assignsvirtual MAC addresses to group members
Active Virtual Forwarder (AVF)All routers which forward traffic for the group
GLBP Load Balancing
Round-Robin (default)The AVG answers host ARP requests for the
virtual router with the next router in the cycleHost-DependentRound-robin cycling is used while a consistenAVF is maintained for each host
WeightedDetermines the proportionate share of hostshandled by each AVF
AVF AVF
AVG
100 200 100
AVF
show vrrp [brief
show track [brie
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FRAME MODE MPLSProtocol Header
MPLS Configuration
! Enable CEFip cef
! Select label protocolmpls label protocol ldp
! Enable MPLS on IP interfacesinterface FastEthernet0/0ip address 10.0.0.1 255.255.255.252mpls ip! Raise MPLS MTU to accommodate multilabel stackmpls mtu 1512
Terminology
Tag Distribution Protocol (TDP)Cisco's proprietary predecessor to LDP
Label Distribution Protocol (LDP)Standards-based label distribution protocol
defined in RFC 3036
Interim Packet PropagationAn LSR temporarily falls back to IP routing
while waiting to learn the necessary MPLSlabel(s)
Label-Switched Path (LSP)The unidirectional path through one or moreLSRs taken by a label-switched packetbelonging to an FEC
Forwarding Equivalence Class (FEC)A group of packets which are forwarded in an
identical manner, typically by destination preand/or traffic class
Troubleshooting
show mpls interfaces
show mpls ldp neighbors
show mpls ldp bindings [detail] (LIB)
show mpls forwarding-table [detail] (LFIB)
show ip cef [detail] (FI
Label (20 bits) Unique label value
Bottom of Stack (1 bit) Indicates label is last in the stack
Time To Live (8 bits) Hop counter mapped from IP TTL
Traffic Class (3 bits) CoS-mapped QoS marking
Label
8 16 24 32
TC S TTL
L2 IP
Label stack
Label Switched Path
Customer (C) IP-only routers internal to customer network
Provider Edge (PE) LSRs on the MPLS-IP boundary
Provider (P) MPLS-only LSRs in provider network
Customer Edge (CE) C routers which face PE routers
Label Protocols
LDP
UDP/646Hello Port
224.0.0.2Hello Address
Proprietary
Adjacency Port
No
TCP/646
PE PE
LSP
Provider Network
Customer Network
P P
P
CE CEC C
TDP
UDP/711
255.255.255.2
Cisco
TCP/711
Conceptual Components
Forwarding/Data PlaneForwards packets based on label or destinatioIP address (includes the FIB and LFIB)
Control PlaneFacilitates label exchange between neighborinLSRs using LDP or TDP (includes the LIB)
Label Switching Router (LSR)Any router performing label switching (MPLS)
Label Information Base (LIB)Contains all labels learned by an LSR via a ladistribution protocol
Forwarding Information Base (FIB)Routing database for unlabeled (IP) packets
Label FIB (LFIB)Routing database for labeled (MPLS) packets
Penultimate Hop Popping (PHP)The second-to-last LSR in an LSP removes thMPLS label so the last LSR only has to performan IP lookup
debug mpls []
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IOS IPV4 ACCESS LISTSStandard ACL Syntax
permit
Actions
deny
remark
evaluate
Allow matched packets
Deny matched packets
Record a configuration comment
Evaluate a reflexive ACL
Extended ACL Syntax
! Legacy syntaxaccess-list {permit | deny} [log]
! Modern syntaxip access-list standard { | }[] {permit | deny} [log]
ACL Numbers
TCP Options
1-991300-1999
IP standard
100-199
2000-2699 IP extended
200-299 Protocol
300-399 DECnet
400-499 XNS
ack Match ACK flag
fin Match FIN flag
psh Match PSH flag
rst Match RST flag
syn Match SYN flag
Troubleshooting
show access-lists [ | ]
show ip access-lists [ | ]
show ip access-lists interface
show ip access-lists dynamic
show ip interface []
show time-range []
! Legacy syntaxaccess-list {permit | deny} [] [] []
! Modern syntaxip access-list extended { | }[] {permit | deny} [] [] []
500-599 Extended XNS
600-699 Appletalk
700-799 Ethernet MAC
800-899 IPX standard
900-999 IPX extended
1000-1099 IPX SAP
1100-1199 MAC extended
1200-1299 IPX summary
urg
established
Match URG flag
Source/Destination Definitions
any Any address
host A single address
Any address matched by the wildcard mask
IP Options
dscp Match the specified IP DSCP
fragments Check non-initial fragments
option Match the specified IP option
precedence {0-7} Match the specified IP precedence
ttl Match the specified IP time to live (TTL)
TCP/UDP Port Definitions
eq Not equal to
lt Greater than
range Matches a range of port numbers
neq
gt
Equal to
Less than
Miscellaneous Options
reflect Create a reflexive ACL entry
time-range Enable rule only during the given time rang
Applying ACLs to Restrict Traffic
interface FastEthernet0/0
ip access-group { | } {in | out}
Match packets in anestablished session
Logging Options
log Log ACL entry matches
log-inputLog matches includingingress interface andsource MAC address
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IPSECProtocols Encryption Algorithms
DES Symmetric 56
Type Key Length (Bits)
AES Symmetric
3DES Symmetric 168
Weak
Strengt
Medium
RSA Asymmetric
128/192/256
1024+
Strong
Strong
Hashing Algorithms
MD5 128
Length (Bits)
SHA-1 160
Medium
Strength
Strong
Internet Security Association and Key ManagementProtocol (ISAKMP)A framework for the negotiation and management ofsecurity associations between peers (traverses UDP/500)
Internet Key Exchange (IKE)Responsible for key agreement using asymmetric
cryptographyEncapsulating Security Payload (ESP)Provides data encryption, data integrity, and peerauthentication; IP protocol 50
Authentication Header (AH)Provides data integrity and peer authentication, but not dataencryption; IP protocol 51
IPsec Modes
IKE Phases
Phase 1A bidirectional ISAKMP SA is establishedbetween peers to provide a secure managemechannel (IKE in main or aggressive mode)
Phase 1.5 (optional)Xauth can optionally be implemented to enforcuser authentication
Phase 2Two unidirectional IPsec SAs are established fodata transfer using separate keys (IKE quickmode)
Transport ModeThe ESP or AH header is inserted behind the IP header; theIP header can be authenticated but not encrypted
Tunnel ModeA new IP header is created in place of the original; thisallows for encryption of the entire original packet
Configuration
crypto isakmp policy 10encryption aes 256hash shaauthentication pre-sharegroup 2lifetime 3600
ISAKMP Policy
crypto isakmp key 1 MySecretKey address 10.0.0.2
ISAKMP Pre-Shared Key
crypto ipsec transform-set MyTS esp-aes 256 esp-sha-hmac
mode tunnel
IPsec Transform Set
crypto ipsec profile MyProfileset transform-set MyTS
IPsec Profile
interface Tunnel0ip address 172.16.0.1 255.255.255.252tunnel source 10.0.0.1tunnel destination 10.0.0.2tunnel mode ipsec ipv4tunnel protection ipsec profile MyProfile
Virtual Tunnel Interface
Troubleshooting
show crypto isakmp sa
show crypto isakmp policy
show crypto ipsec sa
show crypto ipsec transform-set
debug crypto {isakmp | ipsec}
Terminology
Data Origin AuthenticationAuthentication of the SA peer
Data IntegritySecure hashing (HMAC) is used to ensure datahas not been altered in transit
Data ConfidentialityEncryption is used to ensure data cannot beintercepted by a third party
Anti-replaySequence numbers are used to detect anddiscard duplicate packets
Hash Message Authentication Code (HMAA hash of the data and secret key used toprovide message authenticity
Diffie-Hellman ExchangeA shared secret key is established over aninsecure path using public and private keys
L2 IP TCP/UDP
L2 IP TCP/UDP
L2 TCP/UDPIP
ESP/AH
ESP/AHNew IP
Original
Packet
TransportMode
Tunnel
Mode
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IPV4 MULTICASTLayer 2 Addressing
224.0.0.0/24
Group Ranges
224.0.1.0/24
232.0.0.0/8
233.0.0.0/8
Local network contro
Internetwork control
Source-specific
GLOP (RFC 3180)
239.0.0.0/8 Admin-scoped
IGMP Configuration
ip multicast-routing!
interface FastEthernet0/0ip pim {sparse-mode | dense-mode | sparse-dense-mode}ip pim version {1 | 2}
Distribution Trees
Source-RootedProvides the shortest paths from thesource to receivers
SharedA common set of links which carry all
multicast traffic; statically configured
IGMP Troubleshooting
show ip igmp
show ip igmp group
224.0.0.1
Common Groups
224.0.0.2
224.0.1.39
224.0.1.40
All hosts
All routers
Cisco RP Announce
Cisco RP Discovery
IGMP
IGMPv2Adds support for dynamic leave requeand querier election to original IGMP
IGMPv3Adds multicast source filtering to v2
IGMP SnoopingA switch passively inspects IGMPrequests to determine which hostsshould receive multicast traffic
show ip igmp interface
show ip igmp snooping
ip igmp join-group
Terminology
Internet Group Management Protocol (IGMP)Hosts send IGMP requests to local routers to join multicast groups
Reverse Path Forwarding (RPF)Verifies that multicast traffic travels in the reverse direction ofunicast traffic, away from the tree root
Cisco Group Management Protocol (CGMP)A proprietary protocol used by switches to obtain multicastmembership information for end hosts (deprecated)
IGMP Support
IGMP Snooping
Router(config-if)# ip igmp [version ]
Switch(config)# ip igmp snooping
Protocol Independent Multicast (PIM)
Dense ModeThe initial tree encompasses all multicast routers; after a period oftime, routers without IGMP members prune back branches
Sparse-Dense Mode
Allows a PIM-enabled interface to function in either sparse or densemode per group
Sparse ModeThe tree is grown from a central rendezvous point out to themulticast source and recipients
PIMv1Provides automatic RP discovery with Auto-RP (Cisco proprietary)
PIMv2Automatic RP discovery is accomplished by the bootstrap router(BSR) method (standard)
PIM Configuration
RP Configuration
Manual
Auto-RP Mapping Agent
ip pim rp-address
ip pim send-rp-discovery scope
Auto-RP Candidate
BSR Candidate
ip pim send-rp-announce
ip pim bsr-candidate
BSR RP Candidate ip pim rp-candidate
PIM Troubleshooting
show ip mroute
show ip pim interface
show ip pim neighbor
show ip pim rp [mapping]
show ip rpf
IGMPv1Original IGMP specification
239.142.57.6
01-00-5E-0E-39-06
11101111 10001110 00111001 00000110
00000001 00000000 01011110 00001110 00111001 00000110
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IPV4 SUBNETTING
Terminology
Subnets
CIDR
/32 255.255.255.255 1
Subnet Mask Addresses Wildcard
0.0.0.0
/31 255.255.255.254 2 0.0.0.1
/30 255.255.255.252 4 0.0.0.3
/29 255.255.255.248 8 0.0.0.7
/28 255.255.255.240 16 0.0.0.15
/27 255.255.255.224 32 0.0.0.31
/26 255.255.255.192 64 0.0.0.63
/25 255.255.255.128 128 0.0.0.127
/24 255.255.255.0 256 0.0.0.255
/23 255.255.254.0 512 0.0.1.255
/22 255.255.252.0 1,024 0.0.3.255
/21 255.255.248.0 2,048 0.0.7.255
/20 255.255.240.0 4,096 0.0.15.255/19 255.255.224.0 8,192 0.0.31.255
/18 255.255.192.0 16,384 0.0.63.255
/17 255.255.128.0 32,768 0.0.127.255
/16 255.255.0.0 65,536 0.0.255.255
/15 255.254.0.0 131,072 0.1.255.255
/14 255.252.0.0 262,144 0.3.255.255
/13 255.248.0.0 524,288 0.7.255.255
/12 255.240.0.0 1,048,576 0.15.255.255
/11 255.224.0.0 2,097,152 0.31.255.255
/10 255.192.0.0 4,194,304 0.63.255.255
/9 255.128.0.0 8,388,608 0.127.255.255
/8 255.0.0.0 16,777,216 0.255.255.255
/7 254.0.0.0 33,554,432 1.255.255.255
/6 252.0.0.0 67,108,864 3.255.255.255
/5 248.0.0.0 134,217,728 7.255.255.255
/4 240.0.0.0 268,435,456 15.255.255.255
/3 224.0.0.0 536,870,912 31.255.255.255/2 192.0.0.0 1,073,741,824 63.255.255.255
/1 128.0.0.0 2,147,483,648 127.255.255.255
/0 0.0.0.0 4,294,967,296 255.255.255.255
Decimal to Binary
Subnet Mask Wildcard
255 1111 1111 0 0000 0000
254 1111 1110 1 0000 0001
252 1111 1100 3 0000 0011
248 1111 1000 7 0000 0111
240 1111 0000 15 0000 1111
224 1110 0000 31 0001 1111
192 1100 0000 63 0011 1111
128 1000 0000 127 0111 1111
0 0000 0000 255 1111 1111
Subnet Proportion
Classful Ranges
A 0.0.0.0 127.255.255.255
B 128.0.0.0 - 191.255.255.255
C 192.0.0.0 - 223.255.255.255
D 224.0.0.0 - 239.255.255.255
E 240.0.0.0 - 255.255.255.255
Reserved Ranges
RFC 1918 10.0.0.0 - 10.255.255.255Localhost 127.0.0.0 - 127.255.255.255
RFC 1918 172.16.0.0 - 172.31.255.255
RFC 1918 192.168.0.0 - 192.168.255.255
/
/
/
CIDRClassless interdomain routing was developed toprovide more granularity than legacy classfuladdressing; CIDR notation is expressed as /XX
/25
/26/27
/28
VLSMVariable-length subnet masks are an arbitrary lengthbetween 0 and 32 bits; CIDR relies on VLSMs to defiroutes
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IPV6Protocol Header
8 16 24 32
Extension Headers
Ver Traffic Class Flow Label
Payload Length Next Header Hop Limit
Source Address
Destination Address
Version (4 bits) Always set to 6
Traffic Class (8 bits) A DSCP value for QoS
Flow Label (20 bits) Identifies unique flows (optional)
Payload Length (16 bits) Length of the payload in bytes
Next Header (8 bits) Header or protocol which follows
Hop Limit (8 bits) Similar to IPv4's time to live field
Source Address (128 bits) Source IP address
Destination Address (128 bits) Destination IP address
Address Types
Unicast One-to-one communication
Multicast One-to-many communication
Anycast An address configured in multiple locations
Address Notation
Address Formats
EUI-64 Formation
Insert 0xfffe between the two halves of the MA
Flip the seventh bit (universal/local flag) to 1
Special-Use Ranges
::/0
::/128
Default route
Unspecified
::1/128
::/96
Loopback
IPv4-compatible*
::FFFF:0:0/962001::/32
IPv4-mappedTeredo
2001:DB8::/32
2002::/16
Documentation
6to4
FC00::/7
FE80::/10
Unique local
Link-local unicast
FEC0::/10
FF00::/8
Site-local unicast*
Multicast
Hop-by-hop Options (0)Carries additional information which must be examined by everyrouter in the path
Routing (43)Provides source routing functionality
Fragment (44)Included when a packet has been fragmented by its source
Encapsulating Security Payload (50)Provides payload encryption (IPsec)
Authentication Header (51)Provides packet authentication (IPsec)
Destination Options (60)Carries additional information which pertains only to the recipient
Transition Mechanisms
Dual StackTransporting IPv4 and IPv6 across an infrastructure simultaneously
TunnelingIPv6 traffic is encapsulated into IPv4 using IPv6-in-IP, UDP (Teredoor Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)
TranslationStateless IP/ICMP Translation (SIIT) translates IP header fields, NATProtocol Translation (NAT-PT) maps between IPv6 and IPv4 address
Multicast Scopes
1 Interface-local 5 Site-local
2 Link-local 8 Org-local
4 Admin-local E Global
* Deprecated
EUI-64
MAC
Global unicast
Global Prefix Subnet Interface ID
48 16 64
Link-local unicast
Interface ID
64 64
Multicast
Group IDFlags
Scope
1128 4 4
Eliminate leading zeros from all two-byte sets
Replace up to one string of consecutive zeroswith a double-colon (::)
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IS-IS PART 1
Type
Attributes
Algorithm
Metric
Link-State
Dijkstra
Default (10)
AD
Standard
Protocols
Transport
115
ISO 10589
IP, CLNS
Layer 2
Network Types
DIS Elected Yes
Broadcast
Neighbor Discovery YesHello/Dead Timers 10/30
Adjacency Requirements
Interface MTUs must match
Areas must match (if level 1)
System IDs must be unique
Authentication must succeed
show ip route
show ip protocols
show [clns|isis] neighbor
show [clns|isis] interface
show isis database
Levels must match
Protocol Header
IRPD
4 8 12 16
Type Length
Value ...
Packet Length
Version/Protocol ID Extension ID Length
R R R PDU Type Version
Reserved Maximum Area Addresses
NSAP Addressing Authentication Plaintext, MD5
Interdomain Part (IDP)Portion of the address used in routing between autonomoussystems; assigned by ISO
Domain-Specific Part (DSP)Portion of the address relevant only within the local AS
Authority and Format Identifier (AFI)Identifies the authority which dictates the format of the address
Initial Domain Identifier (IDI)An organization belonging to the AFI
High Order DSP (HODSP)The area within the AS
System IDUnique router identifier; 48 bits for Cisco devices (often taken froma MAC address)
NSAP Selector (SEL)Identifies a network layer service; always 0x00 in a NET address
No
Point-to-Point
Yes10/30
Troubleshooting
show isis spf-log
debug isis spf-events
debug isis adjacencies-packets
debug isis spf-statistics
debug isis update-packets
Routing Levels
Level 0
Level 1
Level 2
Used to locate end systems
Routing within an area
Backbone between areas
Level 3 Inter-AS routing
Terminology
Type-Length-Value (TLV)Variable-length modular datasets
Link State PDU (LSP)Carry TLVs encompassing link stateinformation
DIS Election
Highest-priority interface elected
Highest system ID breaks SNPA tie
Default interface priority is 64
Current DIS may be preempted
Highest SNPA (MAC/DLCI) breaks tie
Sequence Number Packet (SNP)Used to request and advertise LSPs; cbe complete (CSNP) or partial (PSNP)
Hello Packet
Establishes and maintains neighboradjacencies
Designated Intermediate SystemA pseudonode responsible for emulatinpoint-to-point links across a multi-accsegment
AFI IDI
47
Area
HODSP
0005.80ff.f800.0000 0001
System ID
0000.0c00.1234
SEL
00
Interdomain Part Domain-Specific Part
Condensed
NSAP
Example
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IS-IS PART 2TLV Types
interface FastEthernet0/0description Area 1ip address 192.168.1.2 255.255.255.0ip router isisisis circuit-type level-1!router isisnet 49.0001.0000.0000.00a2.00
interface FastEthernet0/0description Area 2
ip address 192.168.2.1 255.255.255.0ip router isisisis circuit-type level-1!interface Serial1/0no ip addressencapsulation frame-relay!interface Serial1/0.1 point-to-pointdescription To Area 1ip address 10.0.0.2 255.255.255.252ip router isisisis circuit-type level-2-only! MD5 authentication (keychain not shown)
isis authentication mode md5isis authentication key-chain frame-relay interface-dlci 101!interface Serial1/0.2 point-to-pointdescription To Area 3ip address 10.0.0.9 255.255.255.252ip router isisisis circuit-type level-2-onlyframe-relay interface-dlci 103!router isisnet 49.0002.0000.0000.00b1.00
interface FastEthernet0/0description Area 1
ip address 192.168.1.1 255.255.255.0ip router isisisis circuit-type level-1!interface Serial1/0no ip addressencapsulation frame-relay!interface Serial1/0.1 point-to-pointdescription To Area 2ip address 10.0.0.1 255.255.255.252ip router isisisis circuit-type level-2-only! MD5 authentication (keychain not shown)
isis authentication mode md5isis authentication key-chain frame-relay interface-dlci 101!interface Serial1/0.2 point-to-pointdescription To Area 3ip address 10.0.0.5 255.255.255.252ip router isisisis circuit-type level-2-onlyframe-relay interface-dlci 102!router isisnet 49.0001.0000.0000.00a1.00
Router
RouterRouter A1
10
.0.0.0
/30
10.0.0.4/30
10.0.0.8/30
Area 1192.168.1.0/24
Area 2192.168.2.0/24
Area 3192.168.3.0/24
B2
B3
C2
C3
A2A3
1 Area Addresses
Name
2 IS Neighbors
3 ES Neighbors
Hello, LSP
Use
LSP
L1 LSP
5 Prefix Neighbors L2 LSP
128 IP Internal Reach.
129 Protocols Supported
131 IDRPI
LSP
Hello, LSP
SNP, L2 L
132 IP Interface Address Hello, LSP
6 IS Neighbors
8 Padding
9 LSP Entries
Hello, L2 LSP
Hello
SNP
10 Authentication All
Name Use Name Use
Configuration Example
interface FastEthernet0/0description Area 2ip address 192.168.2.2 255.255.255.0ip router isisisis circuit-type level-1!router isisnet 49.0002.0000.0000.00b2.00
Router
A1
B1 C1
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MARKDOWNHeaders
# Text Text
## Text Text
### Text Text
#### Text Text
##### Text Text
###### Text Text
Blockquotes
> Lorem ipsum> dolor sit amet
Lorem ipsum dolor sit amet
> Lorem ipsum dolorsit amet
Lorem ipsum dolor sit amet
> Level one>> > Level two> >> > > Level three
Level one
Level two
Level three
Lists
* Sizes* Shapes* Colors
* Blue* Green
SizesShapesColorsBlueGreen
1. First2. Second3. Third
1. Alpha2. Bravo
FirstSecondThirdAlphaBravo
Code Blocks
Normal text
#include
Normal text
#includeInline Code
Use `` tags Use
tags``echo `uname -a``` echo `uname -a`
Horizontal Rules
* * *
***
- - -
---
Emphasis
*Emphasis* Emphasis
_Emphasis_ Emphasis
**Strong** Strong
__Strong__ Strong
*Super*emphasis Superemphasis
**Super**strong Superstrong
Escapable Characters
\ Backslash
` Backtick
*
_
{ }
[ ]
Asterisk
Underscore
Curly braces
Square brackets
( ) Parantheses
# Hash mark
+
-
.
!
Plus sign
Hyphen
Period
Exclamation
Links
[Google](http://google.com/) Google
[Google](http://google.com/ "Search") Google
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MEDIAWIKIHeaders
=Text= Text
==Text== Text
===Text=== Text
====Text==== Text
=====Text===== Text
======Text====== Text
Code
Text Text
Text Text
Miscellaneous
Suppress [[wiki]]'''markup'''
Suppress [[wiki]]
'''markup'''
Lists
* Sizes* Shapes* Colors** Blue** Green
SizesShapesColorsBlueGreen
# First# Second# Third
FirstSecondThird
; Term 1 : Foo; Term 2 : Bar; Term 3 : Baz
Term 1FooItem 2BarItem 3Baz
Formatting
''Text'' Text
'''Text''' Text
'''''Text'''''
Text
Text
Text
Text
Text
Templates
Unnamed variables Books by {{{1}}}
Invoking the template {{Author|Palahniuk}}
Named variables Books by {{{name}}}
Invoking the template {{Author|name=Palahniuk}}
Categories
Assign object to a category [[Category:Humor]]
Link to a category [[:Category:Humor]]
Links
[[packet switching]] packet switching
[[packet switching|packet switched]] packet switched
IP [[network]]ing
IEEE [[802.3 (Ethernet)|]]
[http://google.com/]
[http://google.com/ Google]
IP networking
IEEE 802.3
http://google.com/
Google
Images
[[Image:photo.png]]
[[Image:photo.png|Alt text]]
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NETWORK ADDRESS TRANSLATION
interface FastEthernet0ip address 10.0.0.1 255.255.0.0ip nat inside!interface FastEthernet1ip address 174.143.212.1 255.255.252.0ip nat outside
! One line per static translationip nat inside source static 10.0.0.19 192.0.2.1ip nat inside source static 10.0.1.47 192.0.2.2ip nat outside source static 174.143.212.133 10.0.0.47ip nat outside source static 174.143.213.240 10.0.2.181
FastEthernet0
10.0.0.1/16
NAT Inside
FastEthernet1
174.143.212.1/22
NAT Outside
NAT Boundary Configuration
Static Source Translation
Dynamic Source Translation
! Create an access list to match inside local addressesaccess-list 10 permit 10.0.0.0 0.0.255.255!! Create NAT pool of inside global addressesip nat pool MyPool 192.0.2.1 192.0.2.254 prefix-length 24
!! Combine them with a translation ruleip nat inside source list 10 pool MyPool!! Dynamic translations can be combined with static entriesip nat inside source static 10.0.0.42 192.0.2.42
! Static layer four port translationsip nat inside source static tcp 10.0.0.3 8080 192.0.2.1 80ip nat inside source static udp 10.0.0.14 53 192.0.2.2 53ip nat outside source static tcp 174.143.212.4 23 10.0.0.8 23!
! Dynamic port translation with a poolip nat inside source list 11 pool MyPool overload!! Dynamic translation with interface overloadingip nat inside source list 11 interface FastEthernet1 overload
Port Address Translation (PAT)
! Create a rotary NAT poolip nat pool LoadBalServers 10.0.99.200 10.0.99.203 prefix-length 24 type rotary!! Enable load balancing across inside hosts for incoming trafficip nat inside destination list 12 pool LoadBalServers
Inside Destination Translation
Perspective
Location
Local Global
Inside
Outside
Inside Local Inside Glob
Outside Local Outside Glo
Address Classification
Inside LocalAn actual address assignedan inside host
An inside address seen fromthe outside
Inside Global
Outside GlobalAn actual address assignedan outside host
An outside address seen frothe inside
Outside Local
Troubleshooting
show ip nat translations [verbose]
show ip nat statistics
clear ip nat translations
Special NAT Pool Types
Rotary Used for load balancing
Preserves the host portion othe address after translation
Match-Host
Example Topology
Terminology
NAT PoolA pool of IP addresses to be used as insideglobal or outside local addresses in translatio
Extendable TranslationThe extendable keyword must be appendedwhen multiple overlapping static translations
configured
Port Address Translation (PAT)An extension to NAT that translates informatiat layer four and above, such as TCP and UDport numbers; dynamic PAT configurationsinclude the overload keyword
ip nat translation tcp-timeout
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OSPF PART 1Protocol Header
Type
Attributes
Algorithm
Metric
Link-State
Dijkstra
Cost (Bandwidth
AD
Standard
Protocols
Transport
110
RFC 2328, 2740
IP
IP/89
Router Types
Internal RouterAll interfaces reside within thesame area
Backbone RouterA router with an interface inarea 0 (the backbone)
Area Border Router (ABR)Connects two or more areas
AS Boundary Router (ASBR)Connects to additional routingdomains; typically located inthe backbone
Troubleshooting
show ip [route | protocols]
show ip ospf interface
show ip ospf neighbor
* modifiable ospf auto-cost reference-bandwi
Metric Formula
Version Type Length
8 16 24 32
Router ID
Area ID
Checksum Instance ID Reserved
Data
Link State Advertisements
Router Link (Type 1)Lists neighboring routers and the cost to each; flooded within an area
Network Link (Type 2)Generated by a DR; lists all routers on an adjacent segment; floodedwithin an area
Network Summary (Type 3)Generated by an ABR and advertised among areas
ASBR Summary (Type 4)Injected by an ABR into the backbone to advertise the presence of anASBR within an area
External Link (Type 5)Generated by an ASBR and flooded throughout the AS to advertise aroute external to OSPF
NSSA External Link (Type 7)Generated by an ASBR in a not-so-stubby area; converted into atype 5 LSA by the ABR when leaving the area
DR/BDR Election
The BDR also maintains adjacencieswith all routers in case the DR fails
Election does not occur on point-to-point or multipoint links
Default priority (0-255) is 1; highespriority wins; 0 cannot be elected
DR preemption will not occur unlessthe current DR is reset
Virtual Links
Tunnel formed to join two areasacross an intermediate
Both end routers must share acommon area
At least one end must reside in area
Cannot traverse stub areas
Area Types
Standard AreaDefault OSPF area type
Stub AreaExternal link (type 5) LSAs arereplaced with a default route
Totally Stubby AreaType 3, 4, and 5 LSAs arereplaced with a default route
Not So Stubby Area (NSSA)A stub area containing an ASBR;type 5 LSAs are converted to type7 within the area
External Route Types
E1 Cost to the advertising ASBR plus the external cost of the route
E2 (Default) Cost of the route as seen by the ASBR
Authentication
AllSPF Address
AllDR Address
Plaintext, MD5
224.0.0.5
224.0.0.6
Adjacency States
1
2
Down
Attempt
5
6
Exstart
Exchange
3
4
Init
2-Way
7
8
Loading
Full
show ip ospf border-routers
show ip ospf virtual-links
debug ip ospf []
cost =100,000 Kbps*
link speed
The DR serves as a common point fall adjacencies on a multiaccesssegment
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OSPF PART 2
Configuration Example
interface Serial0/0description WAN Linkip address 172.16.34.2 255.255.255.252!interface FastEthernet0/0description Area 0ip address 192.168.0.1 255.255.255.0!
interface Loopback0! Used as router IDip address 10.0.34.1 255.255.255.0!router ospf 100! Advertising the WAN cloud to OSPFredistribute static subnetsnetwork 192.168.0.0 0.0.0.255 area 0!! Static route to the WAN cloudip route 172.16.0.0 255.255.192.0 172.16.34.1
interface Ethernet0/0
description Area 9ip address 192.168.9.1 255.255.255.0ip ospf 100 area 9!interface Ethernet0/1description Area 2ip address 192.168.2.2 255.255.255.0ip ospf 100 area 2! Optional MD5 authentication configuredip ospf authentication message-digestip ospf message-digest-key 1 md5 FooBar! Give C second priority (BDR) in electionip ospf priority 50!
!!!!!interface Loopback0ip address 10.0.34.3 255.255.255.0!router ospf 100! Define area 9 as a totally stubby areaarea 9 stub no-summary! Virtual link from area 9 to area 0area 2 virtual-link 10.0.34.2
interface Ethernet0/0
description Area 0ip address 192.168.0.2 255.255.255.0ip ospf 100 area 0!interface Ethernet0/1description Area 2ip address 192.168.2.1 255.255.255.0ip ospf 100 area 2! Optional MD5 authentication configuredip ospf authentication message-digestip ospf message-digest-key 1 md5 FooBar! Give B priority in DR electionip ospf priority 100!
interface Ethernet0/2description Area 1ip address 192.168.1.1 255.255.255.0ip ospf 100 area 1!interface Loopback0ip address 10.0.34.2 255.255.255.0!router ospf 100! Define area 1 as a stub areaarea 1 stub! Virtual link from area 0 to area 9area 2 virtual-link 10.0.34.3
Route
RouteRouter B
Network Types
DR/BDR Elected
Nonbroadcast(NBMA)
MultipointBroadcast
Neighbor Discovery
Hello/Dead Timers
Defined By
Supported Topology
MultipointNonbroadcast Broadcast Point-to-Point
Yes
No
30/120
RFC 2328
Full Mesh
No
Yes
30/120
RFC 2328
Any
No
No
30/120
Cisco
Any
Yes
Yes
10/40
Cisco
Full Mesh
No
Yes
10/40
Cisco
Point-to-Poin
Area 0
A
BackboneArea 9
Totally Stubby Area
Area 1Stub Area
Area 2Standard Area
WAN172.16.0.0/18
BC
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PHYSICAL TERMINATIONS packetlife.nOptical Terminations
ST (Straight Tip)
SC (Subscriber Connector)
LC (Local Connector)
MT-RJ
Wireless Antennas
RP-TNC
RP-SMA
Copper Terminations
RJ-45
RJ-11
RJ-21 (25-pair)
DE-9 (Female)
DB-25 (Male)
DB-60 (Male)
GBICs
1000Base-SX/LX
1000Base-T
Cisco GigaStack
1000Base-SX/LX SFP
1000Base-T SFP
X2 (10Gig)
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POINT-TO-POINT PROTOCOL
LCP Header
Code Identifier Length
8 16 24 32
General PPP Configuration
! Configure a peer account if authentication will be usedusernamepeer-hostname passwordpassword
! Configure a local IP address pool if neededip pool name first-IP last-IP
interface Serial0/0! Enable PPP encapsulationencapsulation ppp
! Enable CHAP and/or PAP for authenticationppp authentication { chap | pap } [ chap | pap ]
! Enable compressioncompress { predictor | stac }
! Enable peer IP address assignment (server side)peer default ip address { pool name | IP-address }
! Enable IP address negotiation (client side)
ip address negotiated
Troubleshooting
show ppp multilink
debug ppp authentication
PPP Components
Link Control Protocol (LCP)Provides for the establishment, configuration, and maintenance of aPPP link. Protocol-independent options are negotiated by LCP.
Network Control Protocol (NCP)A separate NCP is used to negotiate the configuration of each
network layer protocol (such as IP) carried by PPP.
debug ppp { negotiation | packet }
PPP Header
Address Control Protocol
8 16 24 32
Connection Phase Flowchart
Dead Establish
Authenticat
Network
Terminate
Auth Required
No Auth
Succe
Failure
AdminShutdown
Authentication Protocols
Plaintext Authentication Protocol (PAP)Original, obsolete authentication protocol which relies on theexchange of a plaintext key to authenticate peers (RFC 1334).
Challenge Handshake Authentication Protocol (CHAP)Authenticates peers using the MD5 checksum of a pre-shared secret
key (RFC 1994).
PPP Features
Protocol Multiplexing Multiple NCPs
Optional Compression Stacker/predictor
Loopback Detection Provided by LCP
Load Balancing Multilink PPP
Optional Authentication PAP/CHAP
Multilink PPP Configuration
! Create the multilink interfaceinterface Multilink1ip address IP-address subnet-maskppp multilink group group
! Assign physical interfaces to the multilink groupinterface Serial0/0encapsulation pppppp multilink group group
PPP Summary
Standard RFC 1661
Asynchronous serial, synchronoserial, ISDN, HSSI
Interfaces
PPP Compression Algorithms
Stacker
Replaces repetitive data with symbols from adynamic dictionary (more processor-intensive
PredictorAttempts to predict sequential data (morememory-intensive)
PPP Connection Example
LCP Configuration Request
LCP Configuration Ack
CHAP Challenge
CHAP Response
CHAP Success
IP Control Configuration Request
IP Control Configuration Ack
CDP Control Configuration Request
CDP Control Configuration Ack
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QUALITY OF SERVICE PART 1Quality of Service Models
Layer 2 QoS Markings
Medium
Ethernet Class of Service (CoS)
Name Type
3-bit 802.1p field in 802.1Q header
Frame Relay Discard Eligibility (DE) 1-bit drop eligibility flag
Best Effort No QoS policies are implemented
Integrated Services (IntServ)Resource Reservation Protocol (RSVP) is used to reserve bandwidth per-flow across all nodes in a path
Differentiated Services (DiffServ)Packets are individually classified and marked; policy decisions are made
independently by each node in a path
IP Type of Service (TOS)
Ver HL LenTOS
Precedence
DSCP
Precedence/DSCP
Binary
111000 Reserved
DSCP
56
Prec
7
110000 Reserved48 6
101110 EF46 5
10000032
410001034
10010036
10011038
01100024
301101026
01110028
01111030
01000016
201001018
01010020
010110220010008
100101010
00110012
00111014
000000 BE0 0
CS4
AF41
AF42
AF43
CS3
AF31
AF32
AF33
CS2
AF21
AF22
AF23CS1
AF11
AF12
AF13
ATM
MPLS
Cell Loss Priority (CLP)
Traffic Class (TC)
1-bit drop eligibility flag
3-bit field compatible with 802.1p
IP QoS Markings
IP PrecedenceThe first three bits of the IP TOS field; limited to 8 traffic classes
Differentiated Services Code Point (DSCP)The first six bits of the IP TOS are evaluated to provide more granularclassification; backward-compatible with IP Precedence
QoS Flowchart
Hardware
Queue
Queuing
Decision
Schedule
rSoftware Queue
No
Yes
Software Queue
Software Queue
HW
Queue
Full?
Terminology
Per-Hop Behavior (PHB)The individual QoS action performed at each independent DiffServ node
Trust Boundary Beyond this, inbound QoS markings are not trusted
Tail Drop Occurs when a packet is dropped because a queue is full
PolicingImposes an artificial ceiling on the amount of bandwidth that may beconsumed; traffic exceeding the policer rate is reclassified or dropped
ShapingSimilar to policing but buffers excess traffic for delayed transmission;makes more efficient use of bandwidth but introduces a delay
DSCP Per-Hop Behaviors
Class Selector (CS) Backward-compatible with IP Precedence values
Assured Forwarding (AF) Four classes with variable drop preferences
Expedited Forwarding (EF) Priority queuing for delay-sensitive traffic
Congestion Avoidance
Random Early Detection (REDPackets are randomly dropped
before a queue is full to prevent drop; mitigates TCPsynchronization
Weighted RED (WRED)RED with the added capability ofrecognizing prioritized traffic bason its marking
TCP SynchronizationFlows adjust TCP window sizes in synch, making inefficient use of a link
Class-Based WRED (CBWRED)WRED employed inside a class-based WFQ (CBWFQ) queue
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QUALITY OF SERVICE PART 2Queuing Comparison
Default on Interfaces >2 Mbps
FIFO
Number of Queues 1
Configurable Classes
Bandwidth Allocation
Provides for Minimal Delay
Modern Implementation
No
Automatic
No
Yes
No
PQ
4
Yes
Automatic
Yes
No
No
CQ
Configured
Yes
Configured
No
No
2 Mbps) interfaces
Configurable with the tx-ring-limit interface config command
Provides four static queues whichcannot be reconfigured
Higher-priority queues arealways emptied before lower-priority queues
Lower-priority queues are at riskof bandwidth starvation
Rotates through queues usingWeighted Round Robin (WRR)
Processes a configurable numberof bytes from each queue per turn
Prevents queue starvation butdoes not provide for delay-sensitive traffic
Queues are dynamically createdper flow to ensure fair processing
Statistically drops packets fromaggressive flows more often
No support for delay-sensitivetraffic
Class-Based WFQ (CBWFQ)Low Latency Queuing (LLQ)
WFQ with administrativelyconfigured queues
Each queue is allocated anamount/percentage of bandwidth
No support for delay-sensitivetraffic
CBWFQ with the addition of apoliced strict-priority queue
Highly configurable while stillsupporting delay-sensitive traffic
Flow 1
Flow 2
Flow n
...Hardware
Queue
500 B/cycle
4500 B/cycle
1500 B/cycle
Queue A
Queue B
Queue C HardwareQueue
512 Kbps Min
1024 Kbps Min
Remainder
Queue A
Queue B
DefaultHardware
Queue
512 Kbps Min
1024 Kbps Min
Remainder
Queue A
Queue B
Default
512 Kbps MaxPriority
Hardware
Queue
Show mls qos
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IEEE
Cisco
SPANNING TREE PART 1
BPDU Format
Protocol ID 16
Spanning Tree Protocols
Algorithm
Legacy STP PVST
Defined By
Instances
Trunking
PVST+ RPVST+ MST
Legacy ST
802.1D-1998
1
N/A
Legacy ST
Cisco
Per VLAN
ISL
Legacy ST
Cisco
Per VLAN
802.1Q, ISL
Rapid ST
Cisco
Per VLAN
802.1Q, ISL
Rapid ST
802.1s,802.1Q-200
Configurable
802.1Q, ISL
RSTP
Rapid ST
802.1w,802.1D-2004
1
N/A
Spanning Tree Instance Comparison
STP
C
A B
All VLANs
x
RootPVST+
C
A B
VLAN 1
VLAN 10
VLAN 20
VLAN 30
xx xx
VLAN 1,10 Root VLAN 20,30 RootMST
C
A B
MSTI 0 (1, 1
MSTI 1 (20, x x
MSTI 0 Root MSTI 1 Root
Field Bits
Version 8
BPDU Type 8
Flags 8
Root ID 64
Root Path Cost 32
Bridge ID 64
Port ID 16
Message Age 16
Max Age 16
Hello Time 16
Forward Delay 16
Spanning Tree Specifications
802.1D-1998
PVSTISL PVST+ RPVST+
802.1w
802.1s
802.1D-2004
802.1Q-2003
802.1Q-1998
802.1Q-2005
Link Costs
4 Mbps 250
Bandwidth Cost
10 Mbps 100
16 Mbps 62
45 Mbps 39
100 Mbps 19
155 Mbps 14
622 Mbps 6
1 Gbps 4
10 Gbps 2
Default Timers
Hello
Forward Delay
Max Age
2s
15s
20s
Port States
Disabled
Discardin
Legacy ST Rapid ST
Blocking
Listening
Learning LearningForwarding Forwardi
IEEE 802.1D-1998 Deprecated legacy STP standard
IEEE 802.1w Introduced RSTP
IEEE 802.1D-2004 Replaced legacy STP with RSTP
IEEE 802.1s Introduced MST
IEEE 802.1Q-2003 Added MST to 802.1Q
PVST Per-VLAN implementation of legacy STP
PVST+ Added 802.1Q trunking to PVST
RPVST+ Per-VLAN implementation of RSTP
Port Roles
Root Root
Legacy ST Rapid ST
Designated Designat
BlockingAlternate
Backup
Spanning Tree Operation
Determine root bridgeThe bridge advertising the lowest bridge ID becomes the root bridge
Select root portEach bridge selects its primary port facing the root
Select designated portsOne designated port is selected per segment
Block ports with loopsAll non-root and non-desginated ports are blocked
1
2
3
4
IEEE 802.1Q-2005 Most recent 802.1Q revision
20+ Gbps 1
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SPANNING TREE PART 2PVST+ and RPVST+ Configuration
spanning-tree mode {pvst | rapid-pvst}
! Bridge priorityspanning-tree vlan 1-4094 priority 32768
! Timers, in secondsspanning-tree vlan 1-4094 hello-time 2
spanning-tree vlan 1-4094 forward-time 15spanning-tree vlan 1-4094 max-age 20
! PVST+ Enhancementsspanning-tree backbonefastspanning-tree uplinkfast
! Interface attributesinterface FastEthernet0/1spanning-tree [vlan 1-4094] port-priority 128spanning-tree [vlan 1-4094] cost 19
! Manual link type specificationspanning-tree link-type {point-to-point | shared}
! Enables PortFast if running PVST+, or! designates an edge port under RPVST+spanning-tree portfast
! Spanning tree protectionspanning-tree guard {loop | root | none}
! Per-interface togglingspanning-tree bpduguard enablespanning-tree bpdufilter enable
Troubleshooting
show spanning-tree [summary | detail | root
show spanning-tree [interface | vlan]
MST Configuration
spanning-tree mode mst
! MST Configurationspanning-tree mst configurationname MyTreerevision 1
! Map VLANs to instancesinstance 1 vlan 20, 30instance 2 vlan 40, 50
! Bridge priority (per instance)spanning-tree mst 1 priority 32768
! Timers, in secondsspanning-tree mst hello-time 2spanning-tree mst forward-time 15spanning-tree mst max-age 20
! Maximum hops for BPDUsspanning-tree mst max-hops 20
! Interface attributesinterface FastEthernet0/1spanning-tree mst 1 port-priority 128spanning-tree mst 1 cost 19
Bridge ID Format
Pri Sys ID Ext MAC Address
4 12 48
System ID Extension12-bit value taken from VLAN number (IEEE 802.1t
Priority4-bit bridge priority (configurable from 0 to 61440 increments of 4096)
MAC Address48-bit unique identifier
Path Selection
1 Bridge with lowest root ID becomes the root
2
3
4
Prefer the neighbor with the lowest cost to root
Prefer the neighbor with the lowest bridge ID
Prefer the lowest sender port ID
Optional PVST+ Ehancements
PortFastEnables immediate transition into the forwarding st(designates edge ports under MST)
UplinkFastEnables switches to maintain backup paths to root
BackboneFastEnables immediate expiration of the Max Age timer the event of an indirect link failure
Spanning Tree Protection
Root GuardPrevents a port from becoming the root port
BPDU GuardError-disables a port if a BPDU is received
Loop GuardPrevents a blocked port from transitioning to listeniafter the Max Age timer has expired
BPDU FilterBlocks BPDUs on an interface (disables STP)
RSTP Link Types
Point-to-Point
Connects to exactly one other bridge (full duplex)SharedPotentially connects to multiple bridges (half duplex
EdgeConnects to a single host; designated by PortFast
show spanning-tree mst []
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Command Line Options
-A Print frame payload in ASCII
-c Exit after capturing count packets
-D List available interfaces
-e Print link-level headers
-F Use file as the filter expression
-G Rotate the dump file every n seconds
-i Specifies the capture interface
-K Don't verify TCP checksums
-L List data link types for the interface
-n Don't convert addresses to names
-p Don't capture in promiscuous mode
-q Quick output
-r Read packets from file
-s Capture up to len bytes per packet
-S Print absolute TCP sequence numbers
-t Don't print timestamps
-v[v[v]] Print more verbose output
-w Write captured packets to file
-x Print frame payload in hex
-X Print frame payload in hex and ASCII
-y Specify the data link type
-Z Drop privileges from root to user
Capture Filter Primitives
[src|dst] host Matches a host as the IP source, destination, or either
ether [src|dst] host Matches a host as the Ethernet source, destination, or either
gateway host Matches packets which used host as a gateway
[src|dst] net / Matches packets to or from an endpoint residing in network
[tcp|udp] [src|dst] port Matches TCP or UDP packets sent to/from port
[tcp|udp] [src|dst] portrange - Matches TCP or UDP packets to/from a port in the given rang
less Matches packets less than or equal to length
greater Matches packets greater than or equal to length
(ether|ip|ip6) proto Matches an Ethernet, IPv4, or IPv6 protocol
(ether|ip) broadcast Matches Ethernet or IPv4 broadcasts(ether|ip|ip6) multicast Matches Ethernet, IPv4, or IPv6 multicasts
type (mgt|ctl|data) [subtype ] Matches 802.11 frames based on type and optional subtype
vlan [] Matches 802.1Q frames, optionally with a VLAN ID ofvlan
mpls [] Matches MPLS packets, optionally with a label oflabel
Matches packets by an arbitrary expression
Protocols
arp
TCP Flags
tcp-urg tcp-rst
tcp-ack tcp-syn
tcp-psh tcp-fin
ether
fddi
icmp
ip
ip6
link
ppp
radio
rarp
slip
tcp
tr
udp
wlan
Modifiers
! or not
&& or and
|| or or
Examples
udp dst port not 53
host 10.0.0.1 && host 10.0.0.2
tcp dst port 80 or 8080
UDP not bound for port 5
Traffic between these ho
Packets to either TCP po
ICMP Types
icmp-echoreply icmp-routeradvert icmp-tstampreply
icmp-unreach icmp-routersolicit icmp-ireq
icmp-sourcequench icmp-timxceed icmp-ireqreply
icmp-redirect icmp-paramprob icmp-maskreq
icmp-echo icmp-tstamp icmp-maskreply
TCPDUMP
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VLANSTrunk Encapsulation
VLAN Creation
Switch(config)# vlan 100Switch(config-vlan)# name Engineering
0 Reserved
1 default
1002 fddi-default
1003 tr
Terminology
TrunkingCarrying multiple VLANs over the samephysical connection
Access VLANThe VLAN to which an access port is assigne
Voice VLANIf configured, enables minimal trunking tosupport voice traffic in addition to data traffion an access port
Troubleshooting
show vlan
show interface [status | switchport]
show interface trunk
show vtp status
show vtp password
Access Port Configuration
Switch(config-if)# switchport mode accessSwitch(config-if)# switchport nonegotiateSwitch(config-if)# switchport access vlan 100Switch(config-if)# switchport voice vlan 150
Trunk Port Configuration
Switch(config-if)# switchport mode trunkSwitch(config-if)# switchport trunk encapsulation dot1qSwitch(config-if)# switchport trunk allowed vlan 10,20-30Switch(config-if)# switchport trunk native vlan 10
Trunk Types
Header Size 26 bytes
ISL
4 bytes
802.1Q
Trailer Size 4 bytesN/A
Standard CiscoIEEE
Maximum VLANs 10004094
VLAN Numbers
1004 fdnet
1005 trnet
1006-4094 Extende
4095 Reserve
Native VLANBy default, frames in this VLAN are untaggedwhen sent across a trunk
Dynamic Trunking Protocol (DTP)Can be used to automatically establish trunk
between capable ports (insecure)
Switched Virtual Interface (SVI)A virtual interface which provides a routedgateway into and out of a VLAN
SVI Configuration
Switch(config)# interface vlan100Switch(config-if)# ip address 192.168.100.1 255.255.255.0
ISL
Header
Dest
MAC
Source
MACType FCSISL
DestMAC
SourceMAC
Type802.1Q802.1Q
26 6 6 2 4
6 6 24
Dest
MAC
Source
MACTypeUntagged
Switch Port Modes
trunkForms an unconditional trunk
dynamic desirableAttempts to negotiate a trunk with the far en
dynamic autoForms a trunk only if requested by the far en
accessWill never form a trunk
VLAN Trunking Protocol (VTP)
DomainCommon to all switches participating in VTP
Server ModeGenerates and propagates VTP advertisements to clients;default mode on unconfigured switches
Client ModeReceives and forwards advertisements from servers; VLANscannot be manually configured on switches in client mode
Transparent ModeForwards advertisements but does not participate in VTP;
VLANs must be configured manually
PruningVLANs not having any access ports on an end switch areremoved from the trunk to reduce flooded traffic
VTP Configuration
Switch(config)# vtp mode {server | client | transparent}Switch(config)# vtp domain Switch(config)# vtp password Switch(config)# vtp version {1 | 2}Switch(config)# vtp pruning
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WIRESHARK DISPLAY FILTERS PART 1Ethernet
eth.addr eth.srceth.len
eth.dst eth.trailereth.lg
eth.ig eth.typeeth.multicast
IEEE 802.1Q
vlan.cfi vlan.priorityvlan.id
vlan.etype vlan.trailervlan.len
IPv4
ARP
ip.fragment.overlap.conflictip.addr
ip.checksum ip.fragment.toolongfragment
ip.fragmentsip.checksum_bad
ip.checksum_good ip.hdr_len
ip.hostip.dsfield
ip.dsfield.ce ip.id
ip.lenip.dsfield.dscp
ip.dsfield.ect ip.proto
ip.reassembled_inip.dst
ip.dst_host ip.src
ip.src_hostip.flags
ip.flags.df ip.tos
ip.tos.costip.flags.mf
ip.flags.rb ip.tos.delay
ip.tos.precedenceip.frag_offset
ip.fragment ip.tos.reliability
ip.tos.throughputip.fragment.error
ip.fragment.multipletails ip.ttl
ip.versionip.fragment.overlap
IPv6
ipv6.hop_optipv6.addr
ipv6.class ipv6.host
ipv6.mipv6_home_addressipv6.dst
ipv6.dst_host ipv6.mipv6_length
ipv6.mipv6_typeipv6.dst_opt
ipv6.flow ipv6.nxt
ipv6.opt.pad1ipv6.fragment
ipv6.fragment.error ipv6.opt.padnipv6.plenipv6.fragment.more
ipv6.fragment.multipletails ipv6.reassembled_in
ipv6.routing_hdripv6.fragment.offset
ipv6.fragment.overlap ipv6.routing_hdr.addr
ipv6.routing_hdr.leftipv6.fragment.overlap.conflict
ipv6.fragment.toolongfragment ipv6.routing_hdr.type
ipv6.srcipv6.fragments
ipv6.fragment.id ipv6.src_host
ipv6.versionipv6.hlim
arp.dst.hw_mac arp.proto.size
arp.dst.proto_ipv4 arp.proto.type
arp.hw.size arp.src.hw_mac
arp.hw.type arp.src.proto_ipv4
arp.opcode
TCP
tcp.options.qstcp.ack
tcp.checksum tcp.options.sack
tcp.options.sack_letcp.checksum_bad
tcp.checksum_good tcp.options.sack_perm
tcp.options.sack_retcp.continuation_to
tcp.dstport tcp.options.time_stamp
tcp.options.wscaletcp.flags
tcp.flags.ack tcp.options.wscale_val
tcp.pdu.last_frametcp.flags.cwr
tcp.flags.ecn tcp.pdu.sizetcp.pdu.timetcp.flags.fin
tcp.flags.push tcp.port
tcp.reassembled_intcp.flags.reset
tcp.flags.syn tcp.segment
tcp.segment.errortcp.flags.urg
tcp.hdr_len tcp.segment.multipletail
tcp.segment.overlaptcp.len
tcp.nxtseq tcp.segment.overlap.conflict
tcp.segment.toolongfragmtcp.options
tcp.options.cc tcp.segmentstcp.seqtcp.options.ccecho
tcp.options.ccnew tcp.srcport
tcp.time_deltatcp.options.echo
tcp.options.echo_reply tcp.time_relative
tcp.urgent_pointertcp.options.md5
tcp.options.mss tcp.window_size
tcp.options.mss_val
UDP
udp.checksum udp.srcportudp.dstport
udp.checksum_bad udp.length
udp.checksum_good udp.port
Operators
eq or ==
ne or !=
gt or >
lt or =
le or
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packetlife.WIRESHARK DISPLAY FILTERS PART 2Frame Relay
fr.defr.becn
fr.chdlctype fr.dlci
fr.dlcore_controlfr.control
fr.control.f fr.ea
fr.fecnfr.control.ftype
fr.control.n_r fr.lower_dlci
fr.nlpidfr.control.n_s
fr.control.p fr.second_dlci
fr.snap.ouifr.control.s_ftype
fr.control.u_modifier_cmd fr.snap.pid
fr.snaptypefr.control.u_modifier_resp
fr.cr fr.third_dlci
fr.upper_dlcifr.dc
ICMPv6
icmpv6.all_comp
icmpv6.checksum
icmpv6.option.name_type.fq
icmpv6.option.name_x501
icmpv6.checksum_bad
icmpv6.code
icmpv6.option.rsa.key_ha
icmpv6.option.type
icmpv6.comp
icmpv6.haad.ha_addrs
icmpv6.ra.cur_hop_limit
icmpv6.ra.reachable_time
icmpv6.identifier
icmpv6.option
icmpv6.ra.retrans_timer
icmpv6.ra.router_lifetim
icmpv6.option.cga
icmpv6.option.length
icmpv6.recursive_dns_se
icmpv6.type
icmpv6.option.name_type
RIP
BGP
bgp.mp_reach_nlri_ipv4_prefbgp.aggregator_as
bgp.aggregator_origin bgp.mp_unreach_nlri_ipv4_pre
bgp.multi_exit_discbgp.as_path
bgp.cluster_identifier bgp.next_hop
bgp.nlri_prefixbgp.cluster_list
bgp.community_as bgp.origin
bgp.originator_idbgp.community_value
bgp.local_pref bgp.type
bgp.withdrawn_prefixbgp.mp_nlri_tnl_id
HTTP
http.proxy_authorizatiohttp.accept
http.accept_encoding http.proxy_connect_host
http.proxy_connect_porthttp.accept_language
http.authbasic http.referer
http.requesthttp.authorization
http.cache_control http.request.method
http.request.urihttp.connection
http.content_encoding http.request.versionhttp.responsehttp.content_length
http.content_type http.response.code
http.serverhttp.cookie
http.date http.set_cookie
http.transfer_encodinghttp.host
http.last_modified http.user_agent
http.www_authenticatehttp.location
PPP
ppp.address ppp.direction
ppp.control ppp.protocol
rip.auth.passwd rip.route_tagrip.ip
rip.auth.type rip.routing_domarip.metric
rip.command rip.versionrip.netmask
rip.family rip.next_hop
MPLS
mpls.oam.defect_locationmpls.bottom
mpls.cw.control mpls.oam.defect_type
mpls.oam.frequencympls.cw.res
mpls.exp mpls.oam.function_type
mpls.oam.ttsimpls.label
mpls.oam.bip16 mpls.ttl
ICMP
icmp.checksum icmp.seqicmp.identicmp.checksum_bad icmp.typeicmp.mtu
icmp.code icmp.redir_gw
DTP
dtp.neighbor vtp.neighbordtp.tlv_type
dtp.tlv_len dtp.version
VTP
vtp.vlan_info.802_10_indexvtp.code
vtp.conf_rev_num vtp.vlan_info.isl_vlan_id
vtp.vlan_info.lenvtp.followers
vtp.md vtp.vlan_info.mtu_size
vtp.vlan_info.status.vlan_suspvtp.md5_digest
vtp.md_len vtp.vlan_info.tlv_len
vtp.vlan_info.tlv_typevtp.seq_num
vtp.start_value vtp.vlan_info.vlan_name
vtp.vlan_info.vlan_name_lenvtp.upd_id
vtp.upd_ts vtp.vlan_info.vlan_type